For that matter, when my Boston TV stations do traffic reports, their map shows where the slowdowns are by showing green (no slowdown), yellow (moderate slowdown), or red (severe slowdown). Where do they get such information in what-appears-to-be real time?
Yeah, as I understand it there are two parts to the system: the inputs (which can vary by location) and the information distribution (which is how your GPS nows about). Localities can generate traffic data in many different ways, upload it to the traffic monitoring system, and then your GPS receives the information for it’s current location.
(B) is actually going to be the case soon: apparently iOS 6 (which ships next week) will include anonymous, crowd-sourced traffic info. I assume it will be opt-in; if you do, your phone would report its location and speed to some centralized server. Most likely this would be done using GPS, as I don’t think a cell phone signal alone would provide enough location precision.
GPS is God’s Positioning System. people were getting in traffic jams and cussing and swearing and road rage. telling people to ‘love your neighbor’ wasn’t working here. god then intervened and is sending data direct to you to help keep you peaceful.
road sensors and cameras are monitored by government transportation agencies. they compile this information and send it out in real time.
some GPS units also get land based radio signals which has this real time local traffic data.
A lot of people can’t get their heads around the idea that the satellite doesn’t know your device exists. They think the satellite is telling you your position.
So, Son of a Rich should have asked his boss how all those radio stations can keep track of all those radios all over the world. There must be millions! And that’s not even counting ones in cars! AM and FM! And shortwave!